Distance measuring device and the like



Dec. 25, 1951 Filed July 1i, 1949 Patented Dec. 25, i951 DISTANCE MEASUR-ING DEVICE AND THE LIKE Henry Ernest Lloyd Owen and Henry Thomas Gurton, Chiswiek Village, London, England 3 Claims. l

This invention relates to distance measuring devices and the like and more particularly t such devices for measuring distances on charts and the like.

Navigators and surveyors frequently have to measure distances on charts, maps and the like under diiiicult conditions and the object of the invention is to provide a measuring device to facilitate this task.

According to the invention a device for measuring distances on charts and the like comprises a tubular holder having a toothed chart wheel rotatably mounted thereon and engaging directly or indirectly with a screw threaded rod rotatably mounted on a longitudinal axis within the holder, a screw threaded nut mounted within the holder and threaded onto the rod, the rod or nut being held against axial movement within the holder while the nut or rod respectively is free to move axially within the casing and carriesy a pointer extending transversely through a slot in the holder adjacent to which is a scale or scales on the outer surface of the holder. The arrangement is such that when the chart wheel is rolled over the surface of a chart or the like, it causes the nut or rod to move axially with respect to the holder thus moving the pointer along the scale or scales to record the distance traversed by the chart wheel.

To enable the invention to be more fully understood it will now be described with reference to the accompanying drawings in which:

Fig. 1 is a cross-section through a measuring device constructed according to the invention,

Fig. 2 is a side view of the device shown in Fig. 1 but with the caps omitted.

Fig. 3 is a cross section on the line III-r-III in Fig. 1,

Fig. 4 is a plan view of the cap 50 on the line lV-IV of Fig. 1 looking in the direction of arrow A.

Fig. 5 is a cross section of the chart wheel end of another construction according to the invention,

Fig. 6 is a cross section of the other end of another construction according to the invention,

Fig. '7 is a cross section on the line VII-VII of Fig. 6, f

Fig. 8 is an end view of the cap 5) in Fig. 1 on the line VIII-VIH looking in the direction of the arrow B and Fig. 9 is a cross section of the chart wheel end of another construction according to the invention.

Referring to the drawings, the construction 2 shown in Figs. 1-4 and Fig. 8 shows awchart ineasurer having a tubular holder I3 with an extension i2 on one end thereof on which a toothed chart wheel M is rotatably mounted by means of a pintle l5. A rod i3 journalled in a block 26 fast in the holder ii! is rotatably arranged within theA holder and has a gear wheel 22 rigidly secured thereto so that the teeth project beyond the end of the holder lil and mesh with the teeth on the wheel it. A nut 2i slidably arranged within the casing has an internally screw threaded bore and is screwed onto the rod i3. `A longitudinal slot 26 is provided in the holder I0 and a projection or the like 25 secured to the nut 2d is arranged to extend outwardly through this slot and has a pointer iii on its outer end registering with a scale or scales 32 on the outer face of the holder adjacent to the longitudinal edges of the slot 26.

Thus if the chart wheel is rolled under pressure over a chart, map, plan or the like it revolves and through the gear wheel 22 rotatesA the rod l E to move the nut '24 longitudinally in the holder so that theV pointer 3B moves over the scale 32 to record the distance travelled by the wheel lli over the chart or the like. As the chart wheel I4 is turned the movement of the nut 2 and pointer 3E! will be proportional to the angle through which the ywheel is turned and the scale over which the pointer moves will indicate the` distance through which a point on the periphery of the Wheel has moved. The scaleis marked on the equivalent scale ofthe chart or the like so that the .pointer will record the actual distance represented by the chart along which the 4wheel has been moved. Thrust collars 34 are secured on the rod i8 to prevent axial movement thereof within the casing.

A cylindrical scale sleeve 33 is slidably located on the outside of the holder I8 and is located in position by any suitable -means such as spring rings 38 clipped in grooves di) in the holder. The scale sleeve has longitudinal slot @i3 which when the scale sleeve is in place registers with the slot 2t in the holder. rIhe scale sleeve is double ended and has two scales on either side of the centre dividing line @3 against which the pointer 39 reg* isters. 1t will be understood that one or more scales may be engraved on the outer surface of the holder if desired, additional longitudinal slots being provided in the scale if necessary. The four scales on the scale sleeve 35 are to different measurements such as 1" to 1 mile, 1" to 4 miles, 1 to 1 foot and so on and the scale can be slipped olf the holder over one or other. The

ring 38 is removably retained in an annular recess in the holder and frictionally bears against the end of the sleeve 36. By removal of the ring 38, the scale sleeve 36 may be slid off of the holder and reversed if desired. The scale sleeve may be'made of any suitable material such as plastic,Celluloid or metal and the scales are preferably engraved thereon but may be inscribed or otherwise marked thereon; the scales may be dyed in one or more colours to assist in reading them. The scale sleeve may-'beofftranspai'ent material and spaced away fromthe holder to enable the pointer to slide between the holder and the scale sleeve. The pointer may be-coloured if desired to enable it to be more readily visible.

To facilitate rapid setting offtlie device adu'ick'.- release mechanism may be providedsucli asis shown in Figs. 1-3. For this purpose thenut=24 has a cut away portion 48 (Fig. 3) of such a size .thatthe rod I-8 maybe moved transversely to disengage'he threads'of the nut. The rod is suiiiciently resilient so that owing to its length it will ilex` fonthis purpose. The end of the holder I8 is closed ,by a removable cap 58 having a central bore 52 through which the free end 54 of the rod passes. The bore 52 is elongated into a radial slot 56 (Fig. 8) in linewith the out away portion 48, of kthe nut 24 thereby permitting transverse mmlement f the rod I8. A spring 58 shown in Figs. l' and 4 as D-shaped, but which may be of any suitable known type, is secured in the cap 50. and has ,an indentation 88 (Fig. 4) therein arranged to engage the rod I8 when the cap is in position on the holder. The cap may be held in place. by any knownmeans such as a bayonet Jointonthe spring 6 2showninFigs. 1 and 4. Any known type of blade, Wire annular or Iother clamping spring may be employed.

lfo set the device foruse, the end 54 of the rod'ispressed against the spring 58 to disengage it vfrom the nut 24 which may then be slid in the holder to zeroposition on the scale, by the operatorby means of the pointer 38. The end 54 is then released and is returned by the spring 58 to .the central position to reengage the threads in the nutI 24.

cover 63 may be provided to cover thechart Wheel Whenthe device is not in use. This cap maybe provided with an internal annular groove, ridge or springmember (not shown) `adapted to slip over the ring 38 and hold it in position. Another cover 84 may be provided for the other end ofthe holder and is preferably shaped so that itsopen endV engages the end of the scale sleeve l38 when in position on the holder to secure the scale sleeve in position; in this constructionra ring 38 is not used on this end ofthe holder: or the cover may be formed with an annular groove, ring or spring similar to that on the cover 83 to clip over a ring 38 to that end of the holder. Referringto Fig. 5, the chart wheel I4 is shown as having a conical circumference'which may or may not be milled, roughened or serrated to grip the chart or like surface. The chart wheel has an integral gear wheel 66 meshing with a gear Wheel 68 journalled'on pintle 'I0 in the extensions 'I2 onthe' holder. The Wheel 88 in turn meshes with the Wheel 22. Y v 4' Figs. 6 and '7 show another construction for thev operation of the quick-releaseA mechanism. The cap 58 is secured in place'on the holder I0 by the grub screw 'I4 engaging a circumferential groove 15, in the holder I0, which is shown as extending 'approximately half Way round the holderfbut it need only extend a sufficient dis- 4 tance to ensure displacement and return of the rod I8 as will be explained. The groove 16 and the slot 56 in the cap are so positioned that in one position the rod I8 is held centrally in the slot 55 since the slot 56 extends in the opposite direction to the slot 48 in the nut 54. `Ii the quick release is to be operated the `cap 58 is turned on the holder so that the slots 48 and 56 are in alignment. Pressure on the end 54 of the rod I8 Will now permit the release of the rod from the nut 24. When the pointer has been set the reverse procedure is carried out. It will be seen that -the cap 5D need only be turned through a suiiicient angular distance to lock the rod in position in engagement with the nut thread.

I Ihe abovel-quick release mechanism permit 'rapid' setting of the pointer on the scale, but nal adjustment may be necessary by hand rotation of the chart wheel I4 to effect an accurate setting. The .end rod 54'"of the rod. I8 may be covered by a knob or the like I8 which if desired may be tightened by screwing onto the rod to lock the rod against quick release.

Referring to Fig. 9 a further construction of the chart wheel arrangement is shown. The chart wheel I4 is removably journalled in the extension VI 2 of the holder by means of a lock-nut 88 or the like. The cover 63 is provided with a `container 82 formed with a top 84 removably attached to the cover as by screw threading. This pocket may be used to house spare chart Wheels 88 of different size to the wheel I4; these are preferably complete with pintles and if desired brackets holding the pintles and adapted to be secured tothe end of the holder so that the chart wheel is in mesh with the gear wheel 22; the extension( I2 of the casing is provided with several bores for pintles of different sized chart wheels, or the extension I2 may be adjustably arranged on the holder I8.

It will be seen from the above description that the nut 24 is held by the projection 28 in the slot 26 againstrotation in the holder. In another construction the rod may be slidably arranged inthe holder and' held against rotation, while the nut is held against axial movement in the holder but isV free to rotate therein. The projection 28 and pointer 38 are rotatably mounted on the rod. In thisk construction the gear wheel 22 is mounted on or connected to the nut. It will be appreciated that in this construction the nut or its connection to the gear wheel 22 will extend a substantial distance into the holder which will be longerfor a given length of scale 32 to provide room for the displacement of the rod. The rod may be allowed to project a greater or less distance through the cap 58 ifdesired to reduce the holder length. e l

In the case where the pointer 88 is located beneath the vscale sleeve 38, the sleeve may have several scale'sarranged longitudinally and paralll-v tohodne another around the sleeve, so that by rotating the sleeve the requisite scale may be positioned againstthe pointer. A spring pressed p1uigrf'e1figa`ging/ slots in the end of the sleeve or othermeas may be provided to lock the sleeve in theappropriate position. The use of such a sleeve is advantageous as it keeps the nut and rod free from dirt. e

In measuring the` distance between two points, th wheel must be turned always in the same sense so that the nut mves always in the same direction. To enable the device to be used more readily for measuring distances greater than the distance represented by any one of the scales, pairs of scales running in opposite directions and graduated so as to be a continuation one of the other can be provided. In that case, when the nut has reached the limit of its movement in one direction, the wheel can be made to roll in the opposite sense over the remaining distance to be measured so that the movement of the nut is reversed. The distance Would then be read directly off the continuation scale.

The chart Wheel should have a narrow peripheral surface to enable the user to follow the chart or the like accurately. In use the holder can be held either normally to the surface of the chart or the like or at a considerable angle thereto.

In another construction the nut may be rotatably mounted in the tubular holder, but prevented from axial movement thereon. The rod, screw-threaded and carrying the pointer, or the like, is engaged in the screW-threaded bore Vin -the nut and arranged for axial movement within the holder. The chart wheel through gearing as hereinbefore described causes the nut to rotate and thus move the rod axially within the casing as the chart wheel is moved over the chart or the like. In this case the pointer or the like will be carried on the rod.

In yet another construction the chart wheel is mounted on a bearing bracket rotatably mounted on the tubular holder about an axis substantially parallel or in line With the longitudinal axis of the tubular holder. The axis about which the chart wheel rotates on the bracket is preferably arranged offset from the axis of rotation of the bracket so that this chart wheel assembly will operate in the manner of a castor as the chart Wheel is moved across the chart. In such a construction the chart wheel is prevented from rotation in the wrong direction since if this were attempted the castor action of the chart Wheel assembly would cause the chart Wheel to swing over the dead-centre. However by reversing the direction of movement of the chart wheel over the chart or the like the chart wheel assembly would revolve on the tubular holder through an angular distance of about 180 and this would cause the pointer or the like to record on the holder scale a movement of the chart wheel over the chart equal to about half a turn of the chart wheel. Means are preferably provided to compensate for any such possible inaccurate record on the scale.

The chart Wheel is of thin sheet material, steel or like suitable material and the teeth thereon assist in preventing the wheel slipping over the map or like surface. The chart wheel may be mounted at an angle to the rod axis so that although the teeth mesh with the circumferential teeth of the gear wheel, the diametrically opposite teeth of the chart wheel lie substantially on the axis of the rod.

The measuring device in accordance with the invention can be made of conveniently small size. In the preferred form, it is roughly of the size of a fountain pen and is made so that it can be carried in much the same way as a fountain pen is carried, being provided, if desired, with a clip of the fountain pen type.

The device may be used as a calculator, in which case some or all of the scales may be graduated in other units of measurement, such as Weight, volume or currency values, and so on. Thus, if it is required to calculate the cost of a journey or the fuel consumed, the chart wheel is run over the distance on the chart and the cost of the journey, the fuel consumption or other information may be read direct off the scale. The term measuring as used in the specification and claims is therefore not limited to linear or like measurement, but includes the calculation of other factors related to the distance traversed by the chart Wheel.

We claim:

l. A device for measuring distances on charts and the like comprising a tubular holder having a longitudinal slot through its surface, a screw threaded rod rotatably mounted in said holder to rotate about a longitudinal axis within said holder, a toothed chart wheel rotatably mounted in said holder and operatively connected to said rod to rotate it, a screw threaded nut mounted within said holder and threaded onto said rod, the rod being held against axial movement within said holder and the nut being held against rotation in said holder, a pointer mounted on said nut and extending into said slot, and a sleeve having a pluraiity of different scales mounted on said holder and being adjustable thereon to bring any desired scale into registry with said slot and pointer, a radial slot in said nut to enable said rod to be moved transversely in said holder out of engagement with said nut thread, a cap having a radial Slot therein through which the free end of said rod passes secured against rotation on the end of the holder remote from the chart wheel with the slot in alignment with said slot in said nut, a spring in said cap arranged to maintain said rod in engagement with said nut thread but on movement of said rod -end against the action of said spring will disengage said rod from the nut threads to permit rapid axial movement of said nut and pointer with respect to said scale.

2. A chart measuring device according to claim l in which said spring is D-snaped and is arranged so that its iiat portion engages said rod end to urge the rod into engagement with the nut thread, a detent being formed on said fiat portion normally to position said rod centrally in said holder.

3. A chart measuring device as set forth in claim 1 wherein said sleeve is transparent and iS rotatably disposed on said holder overlying said slot and said pointer therein, said scales comprising circumferentially spaced rows of indicia any row of which may be brought into registry with said slot by rotation of said sleeve on said holder; and detent means for positively maintaining said sleeve in a selected position of registry.

HENRY THOMAS GURTON. HENRY ERNEST LLOYD OWEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 208,101 Kethledge Sept. 17, 1878 997,648 Cavanaugh July l1, 1911 1,383,340 Robbins July 5, 1921 2,188,201 Deidrich Jan. 23, 1940 2,522,030 Fuqua Sept. 12, 1950 FOREIGN PATENTS Number Country Date 48,261 Germany Aug. 15, 1889 103,274 France May 4, 1874 907,924 France July 30, 1945 

